Smoke detector



FIG. 1 is a side elevational view of a smoke detector showing my new design, it being understood that the opposite side is a mirror image thereof;

FIG. 2 is a side elevational view thereof, rotated 90° from that of FIG. 1;

FIG. 3 is a top plan view thereof; and

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a perspective view thereof. 

The ornamental design for an smoke detector, as shown and described. 